Tooth anatomy

Teeth are one of the strongest parts of your body. They are essential for chewing and help you to speak and smile. Keep reading to learn more about the different parts of teeth and the different types of teeth.

Types of teeth

There are four types of teeth found in the adult human mouth.  

 Incisor

The incisors are the front four teeth located in both the top and bottom jaws. The two middle incisors are called the ‘central’ incisors. The teeth next to them are called the ‘lateral’ incisors.  

Canine

There are four canine teeth in the mouth. One canine tooth is located in each corner of the mouth. They are next to the lateral incisors. Canine teeth are the sharpest teeth and are used for tearing food apart.  

Premolar

The premolar teeth are located between the canine and molar teeth. Most adults have eight premolar teeth. There is usually two present in each corner of the mouth. Premolar teeth are used to tear and crush food.  

Molar

The large molar teeth are located at the back of the mouth. They are used to chew foods. Most adults will have twelve molars in total but may only have eight molar teeth present in their mouth. The third molar teeth, which are commonly called ‘wisdom teeth’, often do not fit in the mouth or need to be removed.  
                      

Children have incisors, canine, and molar teeth. Only adults have premolar teeth. The premolar teeth replace the baby molar teeth and the adult molar teeth develop behind these. No baby teeth need to fall out for the adult molar teeth to appear in the mouth. 


The below image shows when each adult tooth appears in the mouth. These ages are a guide only. If you have concerns that your child's adult teeth are not yet present in the mouth when you think they should be, it is best to have their teeth checked by a dentist. If you do not have a dentist, you can find an ADA member dentist near you by using Find-a-dentist.
 

Part of the teeth

Crown

The crown is the part of the tooth that is visible above the gums, inside the mouth.
 

Root

The tooth roots are located below the gum and hold the teeth within the jaw bone. Incisor and canine teeth have one root. Premolars can have one or two roots while upper molar teeth generally have three roots and lower molar teeth have two roots.
 

Enamel

Tooth enamel is the hard, white calcified tooth structure that makes up the outside layer of the crown. It is the hardest substance in the human body and protects the inside parts of the tooth. Tooth enamel cannot repair itself when damaged. There are no nerves in the tooth enamel and it cannot feel pain.
 

Dentine

This is the inside layer of the tooth that is protected by the hard enamel. Dentine is made of tiny tubes with nerve fibres present which gives the dentine feeling. It is yellowish in colour.
 

Cementum

The hard tissue layer covering the surface of the tooth roots. This outer layer is not as strong as enamel.
 

Dental pulp

The soft tissue in the centre of the tooth that contains nerves and blood vessels. It runs down the centre of the tooth root/s connecting to the blood and nerve supply in the surrounding jaw bone.
 

Periodontal ligament

Soft tissue fibres that surround the tooth root connecting the tooth to the surrounding jaw bone.